arm: socfpga: soc64: Support Vendor Authorized Boot (VAB)

arm: socfpga: soc64: Support Vendor Authorized Boot (VAB)

Vendor Authorized Boot is a security feature for authenticating
the images such as U-Boot, ARM trusted Firmware, Linux kernel,
device tree blob and etc loaded from FIT. After those images are
loaded from FIT, the VAB certificate and signature block appended
at the end of each image are sent to Secure Device Manager (SDM)
for authentication. U-Boot will validate the SHA384 of the image
against the SHA384 hash stored in the VAB certificate before
sending the image to SDM for authentication.

Signed-off-by: Siew Chin Lim <elly.siew.chin.lim@intel.com>
Reviewed-by: Ley Foon Tan <ley.foon.tan@intel.com>